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/*
* Application interface library for the AVIRT driver
*
* avirt.h - AVIRT Application interface library header
*
* Copyright (C) 2018, 2019 Fiberdyne Systems Pty Ltd
* Author: Mark Farrugia <mark.farrugia@fiberdyne.com.au>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _AVIRT_H_
#define _AVIRT_H_
#define MAX_STREAMS 16
#define MAX_NAME_LEN 80
#include <alsa/asoundlib.h>
#include <stdbool.h>
/**
* AVIRT Audio Path info
*/
typedef struct snd_avirt_audiopath snd_avirt_audiopath;
struct snd_avirt_audiopath {
const char *uid; /* Unique identifier */
const char *name; /* Pretty name */
unsigned int version[3]; /* Version - Major.Minor.Ext */
// MUST be at the end
struct snd_avirt_audiopath *route_from_ap;
struct snd_avirt_audiopath *route_to_ap;
};
/*
* Audio stream configuration
*/
struct snd_avirt_stream {
const char name[MAX_NAME_LEN]; /* Stream name */
const char map[MAX_NAME_LEN]; /* Stream Audio Path mapping */
unsigned int channels; /* Stream channel count */
unsigned int direction; /* Stream direction */
};
/**
* Audio routing
*/
struct snd_avirt_route {
const char name[MAX_NAME_LEN]; /* Route name */
unsigned int channels; /* Route channel count */
unsigned int direction; /* Stream direction */
struct snd_avirt_audiopath *from_ap;
struct snd_avirt_audiopath *to_ap;
};
/**
* snd_avirt_stream_new - Create a stream in AVIRT
* @name: The name of the stream
* @channels: The number of channels for the stream
* @direction: The stream direction
* (SND_PCM_STREAM_PLAYBACK or SND_PCM_STREAM_CAPTURE)
* @map: The audio path to map this stream to
* @internal: Make the PCM internal.
* @return: 0 on success, negative ERRNO otherwise
*
* Each stream creates a PCM device for the AVIRT sound card.
* Streams will not appear to the user-space until `snd_avirt_card_seal()`
* is called.
*/
int snd_avirt_stream_new(const char *name, unsigned int channels, int direction,
const char *map, bool internal);
/**
* snd_avirt_route_new - Create a route between Audio Paths in AVIRT
* @name: The name of the route.
* @channels: Number of channels for the route
* @direction: The route stream direction
* (SND_PCM_STREAM_PLAYBACK or SND_PCM_STREAM_CAPTURE)
* @from_ap: The Audio Path UID to route audio from
* @to_ap: The Audio Path UID to route audio to
* @return: 0 on success, negative ERRNO otherwise
*
* Allows Audio Paths to be piped together to allow for modular processing
* and/or networking. The "to" Audio Path must be able to accept a stream
* input whose channel count equals to "from" Audio Path's output channel
* count.
*/
int snd_avirt_route_new(const char *name, int channels, int direction,
const char *from_ap, const char *to_ap);
int snd_avirt_routes(struct snd_avirt_route **routes, int *count);
int snd_avirt_streams(struct snd_avirt_stream **streams, int *count);
int snd_avirt_audiopaths(struct snd_avirt_audiopath **audiopaths, int *count);
/**
* snd_avirt_card_configure - Finalize AVIRT stream creation and register sound card
* @return: 0 on success, negative ERRNO otherwise
*
* This should be called once all streams have been created via
* `snd_avirt_stream_new()`. Calling this function will register the AVIRT
* sound card to the user-space, and will configure all mapped lower-level
* Audio Paths for the given stream configuration.
*
* NOTE: Once this function is called, no more streams may be added.
*/
int snd_avirt_card_configure();
/**
* snd_avirt_pcm_info - Get PCM info for a given PCM name
* @pcm_name: The PCM name of which to retrieve the PCM info
* @pcm_info: The PCM info struct to populate
* @return: 0 on success, negative ERRNO otherwise
*
* Can be used to retrieve a `snd_pcm_info_t` struct for a given PCM device from
* it's name. Useful for retrieving card index and PCM index for a PCM.
*/
int snd_avirt_pcm_info(const char *pcm_name, snd_pcm_info_t *pcm_info);
/**
* snd_avirt_card_index_get - Get the ALSA card index for an AVIRT card
* @avirt_idx: The AVIRT internal index (TD MF: perhaps change to UID?)
* @return: The ALSA card index on success, negative ERRNO otherwise
*/
int snd_avirt_card_index_get(int avirt_idx);
/**
* snd_avirt_ctl_set_volume - Set an ALSA mixer volume value
* @name: The ALSA volume control name to set
* @volume: The volume to set
* @return: 0 on success, negative ERRNO otherwise
*/
int snd_avirt_ctl_set_volume(const char *name, long volume);
/**
* snd_avirt_ctl_set_volume - Get an ALSA mixer volume value
* @name: The ALSA volume control name to get
* @volume: Populate this with the gotten value
* @return: 0 on success, negative ERRNO otherwise
*/
int snd_avirt_ctl_get_volume(const char *name, long *volume);
#endif // _AVIRT_H_
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